Kortit II

use std::io::stdin;

pub struct TestInfo {
    pub num_cards: usize,
    pub p1_points: usize,
    pub p2_points: usize,
}

fn recur(
    cards_p2: Vec<usize>,
    c1: usize,
    cpoints_p1: usize,
    cpoints_p2: usize,
    points_p1: usize,
    points_p2: usize,
) -> usize {
    if c1 == 0 {
        if cpoints_p1 == points_p1 && cpoints_p2 == points_p2 {
            return 1;
        } else {
            return 0;
        }
    }
    let mut num_combinations = 0;
    for (index, c2) in cards_p2.iter().enumerate() {
        let (mut cpoints_p1_this_iter, mut cpoints_p2_this_iter) = (cpoints_p1, cpoints_p2);
        if c1 > *c2 {
            cpoints_p1_this_iter += 1;
        } else if *c2 > c1 {
            cpoints_p2_this_iter += 1;
        }
        let mut cp2 = cards_p2.clone();
        cp2.remove(index);
        num_combinations += recur(
            cp2,
            c1 - 1,
            cpoints_p1_this_iter,
            cpoints_p2_this_iter,
            points_p1,
            points_p2,
        );
    }
    num_combinations
}

fn factorial(num: usize) -> usize {
    let mut result = 1;
    for i in 2..=num {
        result *= i;
    }
    result
}

pub fn guaranteed_method(num_cards: usize, num_points_p1: usize, num_points_p2: usize) -> usize {
    let mut cards_p1 = Vec::new();
    let mut cards_p2 = Vec::new();
    for i in (1..=num_cards).rev() {
        cards_p2.push(i);
        cards_p1.push(i);
    }
    let mut a = recur(cards_p2, num_cards, 0, 0, num_points_p1, num_points_p2);
    a = factorial(num_cards) * a;
    a % 1000000007
}

fn main() {
    let mut l = String::new();
    stdin().read_line(&mut l).unwrap();
    let num_tests: usize = l.trim().parse().unwrap();
    let mut tests: Vec<TestInfo> = Vec::with_capacity(num_tests);
    for _ in 0..num_tests {
        let mut tl = String::new();
        stdin().read_line(&mut tl).unwrap();
        let mut nums = tl.trim().split(' ');
        let c: usize = nums.next().unwrap().parse().unwrap();
        let p1: usize = nums.next().unwrap().parse().unwrap();
        let p2: usize = nums.next().unwrap().parse().unwrap();
        tests.push(TestInfo {
            num_cards: c,
            p1_points: p1,
            p2_points: p2,
        });
    }
    for t in tests {
        let a = guaranteed_method(t.num_cards, t.p1_points, t.p2_points);
        println!("{}", a);
    }
}

Test 1

Group: 1, 2, 3, 4, 5

Verdict: ACCEPTED

Test 2

Group: 2, 3, 4, 5

Verdict: ACCEPTED

Test 3

Group: 3, 4, 5

Verdict: TIME LIMIT EXCEEDED

Test 4

Group: 4, 5

Verdict: TIME LIMIT EXCEEDED

Test 5

Group: 5

Verdict: TIME LIMIT EXCEEDED

Test 6

Group: 5

Verdict: TIME LIMIT EXCEEDED